Mobile telephones have been in use for many years. Typically, these systems have comprised a handset which rests in a cradle inside an automobile adjacent the driver's seat. The handset is connected by a cable to a radio transceiver that is located in a remote part of the automobile, such as the trunk. The handset has an earpiece, a mouthpiece and a set of keys for use in dialing telephone numbers. In use, the driver, or one of his passengers, lifts the handset from the cradle, enters a sequence of numbers representing the telephone number of the person he wishes to call, and presses a send button on the handset. This action instructs the radio transceiver to place the call as dialed.
There have been a number of problems and inconveniences associated with the use of such mobile telephones. For example, if a user does not remember the number he wishes to dial, he must refer to a written phone directory, such as one stowed in the vehicle glove compartment In dialing a telephone number, the user must, of course, watch the keyboard or keypad on the handset to make sure he dials the correct sequence of numbers. It is often necessary to hold the handset in one hand in doing this while holding the steering wheel of the car with the other hand. These procedures are not only cumbersome and frequently inaccurately executed, but can actually be dangerous since they require a driver to divert his attention from the road and to handle communication equipment while driving.
Although electronic dictionaries and "Rolodex" systems are old in the art of land line telephone systems, a clear need has existed for an auxiliary apparatus for mobile phone systems that could store and automatically dial telephone numbers while not requiring a driver to fumble with a telephone directory, divert his attention from the road, or attempt to dial numbers manually while driving. Any such apparatus would, however, have to emulate the dialing functions of the existing handset so that the radio transceiver would place telephone calls as if they had been dialed from the handset itself. Thus, data from such an auxiliary dialing system would have to be transmitted to the radio transceiver in a manner that would not interfere with or corrupt data being then sent between the transceiver and the handset. This problem is compounded for the add-on market by the fact that mobile telephone systems are made by a number of different manufacturers and can operate internally in vastly different ways.
Thus, it is the provision of an auxiliary dialing system that overcomes these operative and technical problems to which the present invention is primarily directed.